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The end of IG?

Drier Wall Work’s new system may shake things up.

December 13, 2012  By Paul Drier president of Drier Wall Works

Dear Santa, Can we have a window wall system for our 700 square-foot condo that can save my daddy $350 to $500 a year in energy costs

Dear Santa,
Can we have a window wall system for our 700 square-foot condo that can save my daddy $350 to $500 a year in energy costs, never have a failing IGU, be pre-glazed and unitized, rain screened and multi-chamber pressure-equalized and designed to have more than one inch of tolerance to the structure so we can retro-fit it in place where my current, leaking, fogging and failing window wall currently sits? Please Santa, can we have it?

Drier Wall Works claims its Dual Wall achieves similar energy efficiency performance to double- and triple-glazed IG without the use of an inert gas fill, IG seal or soft coatings.


Thanks, Bobby
Well, Bobby, you may not be asking for enough. A new system exists that can offer higher energy performance than even the latest code (OBC SB10 and 12) requires. It includes a simple and inexpensive maintenance method that keeps the performance of the wall consistently the same for years. It can be developed to integrate free air circulation without an operating window or operating hardware to fail or lose adjustment. The glass can span from floor to ceiling without interruption and still give a U-value of less than 0.26 BTU per square foot per hour. There is no inert gas to dissipate and significantly reduce the energy efficiency of the window over time. No more strange noises from the balcony next door; it achieves a sound transmission coefficient rated in the high 50s.


Maybe you would like to be able to walk over to the window and, with the toe of your foot, bring fresh air into the room whenever you wanted to without worrying if anything will fall out. We are talking here about a system that is future oriented and designed for long-term performance, not a throw-away wall concept your dad will have to replace before you move out. Despite what you may have heard, Santa doesn’t work for free, but this wall system can be built for the same price as current systems out there. The elves have been working on a new system just like this. The only remaining question is, are you on the naughty or nice list?

Santa wouldn’t lie. A system like this does exist. A new company, Drier Wall Works has just announced a new and innovative glass enclosure system that offers all of the above. The system is called Dual Wall and it breaks new ground in an industry that has changed very little in the last 45 years. Dual Wall was rolled out to a select group of architects, contractors, developers, manufacturers, erectors and condo owners in November at an invitation-only presentation called Window to the Future. The technology involved in this new system is so different that more than five inventions and 53 independent claims are now covered by two patents, with more to come.

The system boasts a clean exterior appearance with structurally glazed mullions and horizontals that can span easily from floor to ceiling (window wall) or pass by the structure while resting on the floor (pass-by window wall) or hang directly from the structure (curtain wall). The transition between the configurations is seamless. It is fully shop-glazed, and dry-set unitized, needing no exterior wet seals. It is double rain-screened and multi-chamber pressure equalized. These in themselves are not new technologies, they are tried and true methods used in all the high performance (usually custom) curtain walls. Where the game changes with Dual Wall is that it does not need to use insulated glass units to gain superior thermal and sound performance. It has the ability to be maintained indefinitely and it will continue to perform to specification for the life of the building.

How does it do this? Without giving away any of the elves’ secrets, we can say the following:

The Dual Wall system has a way to balance thermal convection to zero in an air space between the dual glass lights that is more than six times the normal space. It allows for the dual lites of glass to be mounted independently from the framing system. Working with a desiccated air space that has a modular, replaceable, rechargeable desiccant containment system, the space between the glass is humidity-controlled. This new design offers the ability to be maintained indefinitely without ever opening the inside of the building to the outside of the building. The maintenance takes about 10 minutes, about every five years or more. Using dead air thermal spacing technology, it effectively dis-engages the exterior metal surfaces from the interior surfaces and uses the highest thermal separator (dead air) to achieve higher energy performance than any double- or triple-glazed system available today. NFRC thermal models show a U-value of 0.251 BTU per square foot per hour, or an R-value of 3.985. Studies show that in an average 700-square-foot apartment this translates to $500 in energy savings per year for heating. The models were reversed (to see how much could be saved in the cooling process) and found that the U-value for cooling the interior space was 0.241 BTU per square foot per hour. This means it is also cheaper to cool the room in the summer. When we add the saving from heating and cooling together it works out to nearly $750 per year.

Structurally, the system is designed with an eye toward the future. The codes for wind pressure, movement and tolerances are in transition. With all the severe weather that has occurred, many specification writers are starting to change the requirements, adding up to 50 per cent more than the current standards. Dual Wall has been designed with base wind loads of 60 PSF instead of the 40 PSF currently in place. This was done to insure that Dual Wall can meet the future with confidence. Spans of the un-reinforced mullions can vary from nine feet all the way up to over 25 feet depending on elevation and wind load. Dual Wall can be used as a simple window wall, curtain wall or as a pass-by window wall, and the transitions between the three concepts are integrated and seamless. The system can be set from inside or outside with a minimum of labour.

Venting is achieved with an innovative, integrated mechanical venting system that can be controlled with a finger or even your toe. It is internally screened, insulated and contains a ratchet adjuster so the volume of air can be controlled with a simple movement of a control surface. This occurs at every sill, allowing variable and continuous free air when needed. The vent does not intrude or change the sightlines of the vision glass. From either the inside or the outside the vent is invisible.



Dual Wall by the numbers

  • U-value: 0.26 BTU per square foot per hour
  • Sound transmission coefficient: under 60
  • Aluminum grade: 6063-T6 or 6061-T6
  • Allowable building tolerances: 3/4 to 1 ¼ inches
  • Rated wind load: 60 PSF on 48- by 108-inch module

About the author
Paul Drier is CEO and founder of Drier Wall Works. With more than 200 buildings designed and erected around the world over 33 years, he has led design teams for such industry leaders as Guppies, Flour City Architectural Metals, Harnon Contracts, Gassalum and Alumicor. He can be reached at www.drier or e-mail

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